90 XJ Limited remote starter install.

I have been trying to program the RPM learn on my autopage 850lcd remote alarm/starter. I have discovered I tapped into the oil pressure gauge and not the tach feed. I have a 90 XJ 4.0L

I have gone right to the coil and I find that the wire listed at the tach (green wire) delivers 13+ volts while the vehicle is running. This is the same at the tach gauge end. I have checked the Factory service Manual to confirm I have the right wire.

My problem is the alarm install manual says I should be getting between 1-6V not the 13v+ I’m getting.

Do I need to hook the tach wire to something else?

Just go to one of the NOT COMMON injector wires or you can also catch the tach wire going into the PCM. I forget which color it is there though. I do remote starts all the time. So the best place is at the injectors using the wire that is NOT the same color as the others. There will be a common color wire at each injector and the other will be different. Hope this helps.

Thank you. The Green tach wire is what I needed.

I was measuring DC versus the AC signal I should have been.

Once I tapped into the signal behind the cluster the system learned the RPM within seconds.